Mixing device



Feb. 26, 1929.

.F. L. cRADDocK MIX-I NG DEVICE Original Filed July 31, 1923 3 Sheets-Sheet 3 pif/01 Patented Feb. 26, 1929.

UNITED STATES FREDERIC; .or NEW Yonx, N. Y. MIXING nnvron.W

.Application filed July 31, 1923,- Serial N0. 654,825. Renewed April. 4, 1928.

My invention particularly relates to the type of apparatus which is used to stir together and mix food products and other liquids or solids and mixtures of various materials.

A problem which I seek to solve is to provide a mixing device having one or all of the following advantages: low first cost, adjustable, efficient, light weight universal applicability, not liable to accidental damage.

I have found that mixes vary in viscosity and specific gravity and vthat the position of the mixing propeller or equivalent has to be adjusted in depth of submersion. The axis of rotation is usually in a vertical plane parallel with but external to any vertical plane passing through the centre of the tank for the most eiicientresults.

I have also found that the size and shape of the mixing tank affects the location of the ideal position for the mixing propeller, although usuall the propeller shaft works best at a small ang e from the perpendicular. The propeller stream is thus abruptly deflected when striking the bottom and gently deflected by the side of the tank, providing a method for emulsifying and pulverizing the particles of the mix in contrast to the gentler blending and stirring effected in the apparatusof my patent for angular fluid mixers No. 1,548,935, issued August 5, 1925, in which the propeller stream is usually horizontal.

I have also found thatin some cases where air bubbles and froth are desired in the mix different adjustments are required from those where aeration of the mix, or merely a thorough mix, is the desideratum.

The object of my invention is to provide an improved mixing device designed for mounting at the top of a tank, having a screw propeller extending down into the tank and designed to cause the propeller stream to impinge upon a side of the tank whereby the coaction of the propeller stream and the side wall will cause a rolling action of the mix and successively bring all parts of the mix into contact with all other parts thereof.l

Another object of my invention is to provide improved means for mounting my mixing device, preferably at the edge of a tank and preferably by means of an adjustable joint whereby 'the angle of the propeller Stream with respect to the side wall may be varied. A universal joint designed for locky ing in any desiredposition to facilitate both horizontal and vertical adjustment of the 1,703,099 PATENT OFFICE.

HEISSLJED propeller stream is the preferred construction.

Another object of my invention is to provide a mixing device which is universally adjustable and lockable into positions whereby the propeller stream will impinge upon and coact with the side wall o-f a tank to cause a rolling as well as a rotation about a vertical or a horizontal axis alone.

I Another object of my invention is to provide a mixing device which will fulfill the above requirements in an improved manner, preferably using a standard motor, etc., and requiring a minimum of special parts. Another object is to provide improved constructional details for such a device, as may appear from the following description of a preferred construction, and be pointed out in the claims.

Referring to the accompanying drawings:

Fig. 1 is a side view, partly in section of my mixing device clamped to a fragment of the edge of a mixing tank, which is indicated in double dot and single'dash lines;

Fig. 2 is a section taken on the line 2 2 of Fig. 1, particularly showing the clamp and ustable mounting;

Fig. 3 is a section taken on the line 3-3 of Fig. 1, showing additional details of the mounting; l

Fig. 4 is a section of the adjustable mounting, taken on the line 4:-4 of Fig. 3;

Fig. '5 is an enlarged sectional view of the thrust bearing and coupling between the motor shaft and the hollow extension thereof;

. Fig. 6 is an enlarged ctional view of the hand turn grip nut for the telescopic mixing propeller shaft;

' Fig. 7 is a view of the propeller and protector ring, taken on the line 7 -7 of Fig. 1; and

Fig. 8 ,is a cross-section, taken on the line 8-'8 of Fig. 7.

Fig. 9 is a. diagrammatic plan -aziew of a tank provided with an arrow, A, indicating the line of the propeller stream in one of its effective positions coacting with the side and bottom of the tank, and Y Fig. 10 is a. section of Fig. 9 taken on the line 10-10.

The numeral 1 indicates the right-hand side of any tank in which the mix is to be made and The upper portion of the clamp 3 is provided with a hemispherical recess 9 in`which is placed a hemispherical mating casting 11, provided with'a; slot 13, in which is placed a washer 15, having two downwardly extending lugs 17-17 to prevent rotating of the washer 15 with respect to the casting 11.

A bolt 19, havingits head at the lower end, in a recess in clamp 3, extends upwardly through washer 15 and is provided with a conventional washer 21 and nut 23.

Thus the clamp 3 and the casting 11 may be adjustably locked in position with respect to each other by the nut 23. This adjustability is equivalent to that of a ball and socket joint and is universal for any practical position of the mixing propeller 25 in the tank 1.

The casting 11 extends as indicated and surrounds the lower portion of a motor 27, to

' which it is attached by screws 29-29, which enter the taped holes 31-31 found in standard motors of this type.

The casting 1.1 also extends downwardly to form an outboard bearing which contains a grease impregnated wooden bushing 32 for the hollow portion 33 ofthe propeller shaft 33-35. V

At the lower portion of the motor 27 a ballthrust bearing 37 is provided, which abuts against the motor 27 and the hollow shaft 33 to take the upward thrust from the propeller 25, which, when operating, is usually found to be greater than the weight of the motor armature, etc. It is better to have the propeller thrust tliemix down, both to facilitate mixing and to support the weight of the armature or rotor, shaft and propeller and thus reduce the load which must be sustained by a thrust bearing. This arrangement also reduces the stresses on the clamp and the side of thetank and thus reduces breakage of the parts 1n operation.

The motor'shaft 39 andthe hollow shaft 33 are pinned together by a pin 41, and the hollow shaft 33 is provided with a'knurled the propeller, a removable spring shroud ring' 51 is sprung onto the. propeller blades and seated in suitable notches I claim: 1. 'The combination of a tank having a side and containin a mix, a mixing device mounted at the topo the tank, provided with a screw hand-hold 43 and a knurled hand-clamp nut' designed for locking in any desired position,

mounted at the top of the tank, provided with .a screw propeller extending down into the tank and revolvable about an axis in a vertical plane external to the centre axis of the tank, whereby propeller stream of the mix may impingeupon and coact with the side of the tank to' effect a rolling of the mix and a thorough mixture thereof.

3. The combination of a tank having a side wall and a bottom and containing a mix, a mixing device mounted at the top of the tank, provided with a screw propeller extending down into the tank and revolvable about an axis in a* vertical plane external to the centre axis of the adjacent mix in the tank, whereby a propeller stream of the mix may impinge upon and coact with lwall and bottom members of the tank to eli'ect a comb ined action consisting of a rolling of the mix at the wall, a pulverizing at the bottom, anda thorough mixture thereof.

4. The combination of a tank having a side and' a bottom and containing a mix, a mixing device including a universally adjustable mounting and mounted at the top of the tank, provided with a screw propeller extending down into the tank and revolvable about an -axis in a vertical plane external to the centre axis of the tank, whereby a propeller stream of the mix may impmge upon and coact with the side and the bottom of the tank to eEect a combined action consisting of a rolling of the mix at the side, a pulverizing al; the bottom, and a thorough mixture thereo 5. A mixing device provided with attachment means and designed for mounting at the top of a tank having a side, provided' with a screw propeller designed to extend down into the tank and to be revolvable about an axis in a vertical plane external to the centre axis of the tank, whereby a propeller stream of a mix may impinge upon and coact with the side of the tank to effect a rolling of the mix and a thorough mixture thereof.

6. The combination of a tank having a side and containing a mix, a mixing device mounted at the top of the tank including a telescopic shaft provided with a screw propeller extendingl down into the tank and revolvable about an axis in a vertical plane external to the centre axis of the adjacent mix in the tank at a preferred height xed by the then extension of the telescopic shaft, whereby a propeller stream of the mix may impinge upon and coact at a preferred height with the side of the tank to efeet a rolling of the mix and a thorough mixture thereof.

7. The combination of a tank having a side and containing a mix, a mixing device mounted at the top of the tank, provided with a screw propeller extending down into the tank and revolvable about an axis in a vertical plane external to the centre axisl of the adjacentmix in the tank, whereby a propeller stream of the mix may impinge upon and coact with the side of the tank to eect a rolling of the mix and a thorough mixture thereof, and means to adjust the position of the `propeller axis with relationrto the axis of the mix.

8. The ombinationof a tank having a side and containing a mix, a mixing device mounted upon a ball and socket adjustable bracket at the top of the tank, provided with a screw at the top of the tank, provided with a telescopic shaft carrying a screw propeller ex.-

tending down into the tank and revolvable about an axis in a vertical plane external to the centre axisof the adjacent mix in the tank,

-Whereby a propeller stream of the mix may impinge upon and coact with theside of the tank to effect a rolling of the mix and a thorough mixture thereof.

VFREDERICK L- CRADDOCK. 

